There's Science in Your Garbage

Have you ever wanted to be a detective? Some detectives help solve crimes. Some detectives, called archaeologists (ar-kee-AHL-uh-jists), learn how ancient people lived by studying what they left behind: pottery, artwork, even bones.

Other detectives solve puzzles about our modern lives by looking at what we throw away. They study garbage.

Dr. William Rathje (RATH-jay) is a professor at the University of Arizona. He directs The Garbage Project, which has been studying garbage for more than 25 years. He and other teachers and students have arranged with local city officials to have garbage from different neighborhoods delivered to them instead of taking it to the landfill. They sort through all the garbage and record every piece. Sometimes they also go out to landfills and dig up old garbage.

They examine every item that has been thrown out. To do this, they wear boots, long pants, long-sleeved shirts, aprons, gloves, even helmets and face masks. These keep them from being scratched or stuck. Face masks also help with the smell.

"It might seem like an awful smell to people," Dr. Rathje says. "But my German shepherd thinks it's wonderful." The smell is from gases created as garbage breaks down (decomposes).

The smelliest gunk

What kind of garbage smells the worst? "Definitely raw, spoiled chicken," Rathje says. "It's bad enough to make anyone want to turn and run."

One way to keep down the smell and mess is to freeze the garbage before sorting it. This also keeps down the number of flies. And it can turn up a few surprises. One worker found a frozen lizard in his garbage. He set it out in the sun. After it warmed up for a while, it crawled away.

The Garbage Project doesn't look at garbage from a single person or home. They study what a group of people throws away. This helps them find patterns in how people live.

What can you learn from studying trash? Sometimes you find important information about our habits. For example, children really don't eat their vegetables. Neither do adults. Leftover produce is the biggest part of food waste.

People also say they eat a lot more liver than they really do. How can "garbologists" know this? They ask people in an area how much liver they eat. Then they study the garbage from that area and look for liver that's been thrown away and for empty meat packages that had liver in them. This helps them figure out how much liver people bought and how much they actually ate.

Garbologists also discovered that we waste a lot more food than we think. Lessons like this can help us learn how to cut down on waste. We may not give up eating vegetables, but we might find ways to serve them that make us enjoy them more.

Telltale trash

Sometimes it takes real detective thinking to learn what garbage is telling us. One example is the discovery that poorer people pay more for food than richer people pay. Garbage Project workers learned this when they compared garbage from poor and rich neighborhoods. From the empty cans, boxes, and packages, they saw that poorer people bought food in smaller packages. That's all they can afford to buy at one time. Richer people bought larger packages that may cost more but give more for the money.

Studying garbage also helps us by showing what doesn't turn up. When the number of plastic containers or glass bottles in garbage goes down, it may mean that more are being recycled. In the past few years, the number of batteries being thrown away has gone down. And many newspapers no longer use ink that contains heavy metals, like lead.

We can also learn what types of garbage take up the most space in our landfills. Paper is the big winner - or rather, loser. It takes up more than 40 percent of our landfill space. Much of that paper could be recycled.

But the best way to cut down on garbage is source reduction, Rathje says. This means using things more wisely. "If we wrote on both sides of every piece of paper, instead of just one side, we would use half as much paper and have half as much to throw away," he points out.

Taking a good look at our garbage can help us figure out how to produce less of it, and how to get rid of it safely. By searching through our trash, modern archaeologists teach us about ourselves and our habits.

And about the sturdiness of frozen lizards.

Trashy Mysteries

Let's see if you can be a garbage detective. Here's something The Garbage Project found. Can you use it to answer some questions?

After Halloween, lots of empty candy wrappers are in the garbage. After Valentine's Day, there are a lot of candy wrappers, and many still have candy in them.


1.Who likes to eat candy the most?

a. sweethearts

b. kids

c. garbage collectors

2. What do people like best about valentine gifts?

a. throwing them away

b. eating the candy

c. getting a present in the first place

3. What probably turns up a lot in the garbage a week after Mother's Day?

a. flowers

b. mothers

c. phone bills

4. Which is most likely to be in the trash?

a. a shirt

b. an award certificate

c. wrapping paper

Answers: 1. b; 2. c; 3. a; 4. c.

Be a Garbage Detective

Your school may be a good place to begin, suggests Garbage Project Director William Rathje. Ask a teacher if your class can study the school's garbage one day. Sort through the garbage after lunch and search for these clues:

How much food is wasted? You might weigh all the garbage first, and then weigh just the discarded food to find out. If the food weighed 50 pounds and all the garbage weighed 100 pounds, you would know that half of the trash at your school is food waste.

What types of food are thrown away the most? This could help the school decide if some food should not be served as often or perhaps in smaller portions.

How much paper is thrown away? Look carefully at the paper to see if any is wasted. Are there many blank sheets? Are the sheets used only on one side? What types of paper are thrown away most: student work, office forms, construction paper?

Is anything thrown away that shouldn't be? Sometimes things end up in the garbage by accident. Or they could be fixed and reused.

After your trashy detective work, discuss your findings. Can your class think of ways to reduce the garbage at school? You could also start a campaign to help students reduce waste themselves.

Check out this Web site:

This "Newton's Apple" (a PBS-TV show) site helps kids become "waste watchers." It has hands-on activities and suggestions for visiting a landfill or recycling center.

Questions, comments, ideas? Write: Kidspace, c/o CSM, One Norway St., Boston, MA 02115. Or e-mail

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